Simplify the following expression: $z = \dfrac{6}{6a - 10} \div \dfrac{8}{5a}$
Answer: Dividing by an expression is the same as multiplying by its inverse. $z = \dfrac{6}{6a - 10} \times \dfrac{5a}{8}$ When multiplying fractions, we multiply the numerators and the denominators. $z = \dfrac{ 6 \times 5a } { (6a - 10) \times 8}$ $z = \dfrac{30a}{48a - 80}$ Simplify: $z = \dfrac{15a}{24a - 40}$